NSC800 High-Performance Low-Power CMOS Microprocessor
June 1992
NSC800
TM
High-Performance
Low-Power CMOS Microprocessor
General Description
The NSC800 is an 8-bit CMOS microprocessor that func-
tions as the central processing unit (CPU) in National Semi-
conductor鈥檚 NSC800 microcomputer family National鈥檚
microCMOS technology used to fabricate this device pro-
vides system designers with performance equivalent to
comparable NMOS products but with the low power advan-
tage of CMOS Some of the many system functions incorpo-
rated on the device are vectored priority interrupts refresh
control power-save feature and interrupt acknowledge The
NSC800 is available in dual-in-line and surface mounted
chip carrier packages
The system designer can choose not only from the dedicat-
ed CMOS peripherals that allow direct interfacing to the
NSC800 but from the full line of National鈥檚 CMOS products
to allow a low-power system solution The dedicated periph-
erals include NSC810A RAM I O Timer NSC858 UART
and NSC831 I O
All devices are available in commercial industrial and mili-
tary temperature ranges along with two added reliability
flows The first is an extended burn in test and the second is
the military class C screening in accordance with Method
5004 of MIL-STD-883
Features
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Fully compatible with Z80 instruction set
Powerful set of 158 instructions
10 addressing modes
22 internal registers
Low power 50 mW at 5V V
CC
Unique power-save feature
Multiplexed bus structure
Schmitt trigger input on reset
On-chip bus controller and clock generator
Variable power supply 2 4V
b
6 0V
On-chip 8-bit dynamic RAM refresh circuitry
Speed 1 0
ms
instruction cycle at 4 0 MHz
NSC800-4
4 0 MHz
NSC800-35 3 5 MHz
NSC800-3
2 5 MHz
NSC800-1
1 0 MHz
Capable of addressing 64k bytes of memory and 256
I O devices
Five interrupt request lines on-chip
Block Diagram
TL C 5171 鈥?73
NSC800
TM
is a trademark of National Semiconductor Corp
TRI-STATE is a registered trademark of National Semiconductor Corp
Z80 is a registered trademark of Zilog Corp
C
1995 National Semiconductor Corporation
TL C 5171
RRD-B30M105 Printed in U S A